The First Example of 4,7,8,9‐Tetrahydrothieno‐[2,3‐d]azocine Synthesis by Domino Reaction of 4‐Aryl‐4,5,6,7‐tetrahydrothieno[3,2‐c]pyridines with Activated Alkynes.

It is shown that the expansion of the tetrahydropyridine fragment requires the presence of an aryl substituent at position 4 of the tetrahydrothieno[3,2-c]pyridines as it stabilizes the intermediate acyclic zwitterion.